Automatic press tool for straightening or bending



July 3, 1945. F. s. SAUNDERS AUTOMATIC PRESS TOOL FOR STRAIGHTENING OR BENDING 2 Sheets-Sheet 1 Filed Feb. 1 5,'194s Inventor W I A tlorney y 1945' f F. s. SAUNDERS 2,379,658

' AUTOMATIC PRESS TOOL FOR STRAIGHTENING OR BENDING Inventor Attorney The present invention [relates to automatic press tools and it has forits object the provision of a machine capable of being connected to the ram of i any existing press forthep'urpose of of pistons slidably mounted therein; a valve at the head of each cylinder, means mechanically actuated for maintaining the valves inthe open straightening or bending to correct form trans i verseorlongitudinalcontours;

i AUTOMATIGPRE-SS 'roomvoasm Amurr- Y i WLENINGORBENDINGMM 1 1, t flank Stanlev saiinders, (lardifftsoutnw k a a l ApplicationFebruarylfi, 1943,Seria1 No; 475,922 i Ii l wlIn.GreatiBritain May .1,1941i ,M

'10 p therein" by means of a plurality of equallytspaced 'circumferentially disposed collars I 9. The under position, means automatically actuatedfor maintainine saidvalves-in the closed position and a self-aligning pad on the lowerend of each piston,

with, or without, means for locking anyone or more of the pistons out Of ODGI'GItiOII. In the accompanying drawings whichillustrate an embodiment of this invention-- i l Figure 1 is a side elevationof the tool.

Figure 2isaplan; i Figure 3'is anend elevationwith certain; ex-

terna1partsomitted;and,

' Figure 4 is a vertical section on line IV-IV of Figure 3. v In thedrawings the machine comprisesjan oblong shaped block I provided in thelower part "thereof with a plurality of cylinders 2 arranged side-byeside'in the same plane,"eachcyl inder containing a p'istoniflThe lowerparfljofjthe block If is extendedbelow the lowerend of the cylindersjbyineans of endplates 4 andside plates 5 for the purpose hereafter described. The upper end of each piston is providedwith a cup leatherfs andapproximatelyjhalf the lengthof each piston at its lower end is of rectangular ranged; to hbear against the side platesi while'lthe ,with an arcuate recess adapted to receive and forzn the seat fora self-aligning element 8 pro vided l with a hat surface to; which is secured a a pad of aluminium or the glike 9, i said elements being supported inppositioniagainst their respectiveseats by links l0,provided' atxeach end of a the element so that theymayturn freelymontheir respectiveseatings as hereafter d'escribed For the. purpose of limiting the riserand fall of the pistons. thetside plate 5 may :be furnished with vertically; disposed slots l and; the .1 rectangular r of fluted pins zl theilowerf endsiof which nest arrangement beingzsuchthatwhen the element a lower portion 1 of a the pistons with projections seriesof valves with a horizontallyt disposedchore l1 adaptedl todreceivei a: non-rotatable sliding valve operating "element is oil smaller diameter than thelbore I] but concentricallyiusup i rted part of t i lement l8 betweenath-ei collars IB- is provided with equally spaced cam surfaces. 20; with which the. upper. ends of 1 a icorrespondinginumbei on the ball valves h5g1 are adapted to coach; the

l81is1in one position all theball valves areinQth'e closedlzposition, but when moved into the other position all: said valves: are JfQFCBdA on? their seats by; the consequent depression; of therpinsz It f The movement of the sliding element ii81to=open the valves is.leffectedsmechahicallyby means of la spring 22 arranged at conenendwofi said= element whereas said valves are maintainediin tithe closed position automatically by fluid pressure acting on arcup leather 23 secured to the opposite end of said sliding element 118, set up by the oilz'distplaced from" the: cylindersii iiincreasing the Ifluid -21? and pipes 28.

1 whenlthel tool i isnot use a; pistons. 3 an be; in theirulowermost or 1 extended position; the

valve operating elements"; willtbe forcediby; the spring 22 to theleft andall the valve pins 21 will be depressed by the cam surfaces-topper;

the valves.

For use: the" tool" is secured by the-part to the lowerendlof, the ram ofsa press and the w ork,

which may consist .ofwthe bentblade' of an air screw indicatedin crosssection at X in Figured is set up and suitablyisupported at the tipan'd boss beneath the tool so that thewplungers are disposed :transverselyt Lofwth'e blade. When ithe parts a are thus disposed, i the \operator depresses .the pedal *ofthe press which brings the-pads! ontheselfaaligningelementsfl into contact lwith the uppersurface of the. blade :to1 be bent, :as1the .first :pad makes contact its r piston is: forced cup the oil displaced from thelcylinder .labove the piston actuated passes" through the lball" valve into the bore 11 and the :fluid pressure in the bore and: bottles 24 24 isisthereby. slightly increased :and this operation continues as-ftheitooltis grade it ually lowered and the several pads make contact with the surface of the blade. When all the pads 8 are in contact with the work and lowering of the ram and thereby the tool continues the pistons will remain stationary, whereas the block, being carried on the end of the ram continues to move downwards thus causing the cylinders to move downwardly over the pistons thereby causing further oil to pass through the ball valves l into the bore l1 and past flutings 26 in the collars l9 and through the passages 21, 2'! into pipes 28 and bottles 24, 24 At the same time the oil from passage 21 alsopasses along channel 2'l into the end I'l of the bore I! which end I'I is thus through the passage 2'! open to the pressure in the bottle 24 this causes a pressure to be built up on cup leather 23 which corresponds with the pressure created in the bottles 24, 24 by oil being forced into them against the existing.

atmosphere pressure.

When the pressurein the part I! and associated parts has risen to such an extent as to exceed the pressure of the spring 22, the element I8 is forcedlto the right thereby permitting the pins 2| to rise and the ball valves to close thus preventing the further passage of oil from the cylinders 2. At this point independent movement of the pistons ceases and said pistons, the body ofthe tool and the ram become a rigid whole and descend'together the pads 9 all pressing evenly againstthe surface of. the blade being bent or straightened. When the operator has decided that sufficient bending has been performed, the

operating pedal or lever of the press is released and 'the ram commences to rise. Immediately theload is oifthe tool, the pressure within the .cylinder 2 is relieved and this allows the pressures build up in the bottle 24, 24 bore I1, I1 passages 21 and 21 to overcome the ball valves l5. which open, the load acting against the cup leather 23 is reduced and the element I8 is forced to the :left by the spring 22 and the air pressure in the bottles 24 returns the displaced oil into the several cylinders 2 until the pistons are once again in the lowermost position. It will thus be seen that'the' tool is entirelyautomatic in its operation.

It will be appreciated that the curve of the surface of the article being worked on determines the final position-of the pistons and the amount of oil displaced from the cylinders 2 to the bottles 24, 24 and this in turn controls the air pressure in the bottles and affects the amount of tension or! the spring22 and this spring must be suitably adjusted according tothe conditions by the tensioning device 29 or by anyother suitable means.

To" enable wide and narrow surfaces to be pressed, the two end pistons can be locked out of action by pushing same upwardly into the highest position in their respective cylinders to bring a hole-30 (Figure 4) in the pistons into coincidence with a hole 3| (Figure 1) provided in the cylinder :walls and inserting a pin32..

Care must be takento see that the. pressure -in.the bottles 24, 241 does not exceed atmospheric pressure when all the pistons are in the lowermost position and that the correct quantity of oil is inserted into the tool, in the first place to enable the pistons to take up the correct contour of the work and secondly to, enable the two end pistons tobe raised and retained in their highest position if desired, without creating a pressure suffi- ,cient to operate-the element I8. Should this lat- ;ter condition be created it may be readily overcome by. adjusting the screw 29 to increase the pressure of the spring 22.

From the foregoing it will be understood that there is a direct relation between the pressure exerted by the spring slidably mounted in each cylinder each of said pistons being free to take up a position in its cylinder according to the contour of the surface being acted on, a valve at the head of each cylinder,

means mechanically actuated for simultaneously opening and maintaining all said valves in the open position and means automatically actuated for simultaneously closing and maintaining all said valves in the closed position, the pistons being thereby locked against further independent movement. i v

2. An automatic press tool for straightening and bending as claimed in claim 1, in which the lower part of the block element is provided with side and end plates and in which the upper ends of the pistons sliding in the cylinders formed in the block are of cylindrical form, the lower a parts of said pistons being of rectangular form fitting closely against each other and against said side and end plates, arcuate recessesprovided in the lower end of each rectangular part and a self-aligning work-engaging pad rotatively mounted in each of said recesses.

3. An automatic press tool for straightening and bending, comprising a block element furnished with a plurality; of cylinders, a piston slidably mounted in each cylinder, a ball valve at the upper end of each cylinder, a valve controlling element slidably arranged in said block element above said ball valves, fluted pins interposed between and coacting with said valve controlling element and ball valves, mechanical means comprising an adjustable spring for actuating 'the valve controlling element for maintaining the valves in the open position, fluid pressure means opposing the adjustable spring for actuating the valve controlling element for maintaining said valves in the closed position, and a self-aligning work-engaging pad on the lower end of each piston.

4. An automatic press tool for straightening and bending, comprising a block elementfurnished witha plurality of cylinders, a piston slidably mounted in each cylinder, a spring controlled ball valve provided at the upper end of each cylinder, a non-rotating horizontally disposed valve controlling element slidably arranged in said block element above'said ball valves, a

. plurality of cam surfaces provided on said valve controlling element, fluted pins interposed between and coacting with said cam surfaces and ball valves, mechanically actuated means comprising an'adjustable spring for maintaining the valves in the open position, fluid pressure actuated means opposing the adjustable spring 'for maintaining said valves in the closed position,- a

self-aligning work-engaging pad on the lower end of each piston a'ndmeans for locking certain of the pistons'out of action."

5. An automatic press tool'for straightening and bending, comprising a block element furnished with a plurality of cylinders, apiston slidablymounted in each cylinder, a spring controlled ball valve provided at the upper end of each cylinder, a horizontally disposed bore provided in said block element above said ball valves, 9. non-rotating valve controlling elementslidably arranged in said bore, a plurality of cam surfaces provided on said valve controlling element, fluted pins interposed between and coacting with said cam surfaces and ballvalves, mechanically actu- 1 ated means comprising an adjustable spring for maintaining the valves in the open position, fluid 7 pressure actuated means opposing the adjustable spring for maintainingsaid valves in the closed position, a self-aligning work-engaging pad on the lower end of each piston and means for: locking certain of the pistons out of action. a V j n FRANK STANLEY SAUNDERS 

